The present invention relates to a family of new porphine compounds for use as colorants and/or colorant stabilizers. The new porphine compounds may be used alone or may be used in combination with one or more colorants to provide light stability to colorants. The present invention further relates to...http://www.google.ca/patents/US6524379?utm_source=gb-gplus-sharePatent US6524379 - Colorants, colorant stabilizers, ink compositions, and improved methods of making the same

The present invention relates to a family of new porphine compounds for use as colorants and/or colorant stabilizers. The new porphine compounds may be used alone or may be used in combination with one or more colorants to provide light stability to colorants. The present invention further relates to inks containing the new porphine compounds and a method for making the new compounds. The present invention also relates to improved methods of making porphines. The improved processes allow the production of porphines at lower cost and higher yields compared to conventional methods of making porphines.

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Claims(37)

What is claimed is:

1. An ink composition comprising a porphine having the following general formula:

where M is iron, cobalt or copper; R represents a halogenated alkyl group,

wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a substituted alkyl group; an aryl group; a substituted aryl group; an alkoxy group; a nitrogen-containing group; a sulfur-containing group other than —SR′, wherein R3, R8, R13, and R18 are not concurrently sulfur-containing groups; —OR′, —NR′R″, or —SR′, wherein R′ and R″ each independently represent an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group.

2. The ink composition of claim 1, wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a nitrogen-containing group; or a sulfur-containing group other than SR′.

9. The ink composition of claim 1, wherein the composition further comprises a colorant, a molecular includant, a chelating agent, or a combination thereof.

10. The ink composition of claim 9, comprising a molecular includant.

11. The ink composition of claim 10, wherein the molecular includant is one or more cyclodextrins.

12. The ink composition of claim 11, wherein the one or more cyclodextrins comprise α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, δ-cyclodextrin, hydroxypropyl β-cyclodextrin, or hydroxyethyl β-cyclodextrin.

13. A porphine compound having the following general formula:

where M is iron, cobalt or copper; R represents a halogenated alkyl group,

wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a substituted alkyl group; an aryl group; a substituted aryl group; an alkoxy group; a nitrogen-containing group; a sulfur-containing group other than —SR′, wherein R3, R8, R13, and Rl8 are not concurrently sulfur-containing groups; —OR′, —NR′R″, or —SR′, wherein R′ and R″ each independently represent an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group.

14. The porphine of claim 13, wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a nitrogen-containing group; or a sulfur-containing group other than SR′.

forming a first reaction mixture of one or more aldehydes, pyrrole, a substituted toluene compound, and a solvent;

heating the first reaction mixture to form a porphine precursor;

removing the solvent to yield a precursor precipitate;

mixing the precipitate with propionic acid to form a second reaction mixture;

heating the second reaction mixture at reflux to yield the porphine.

19. The method of claim 18, wherein the one or more aldehydes comprises one or more of

wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a substituted alkyl group; an aryl group; a substituted aryl group; an alkoxy group; a nitrogen-containing group; a sulfur-containing group; —OR′, —NR′R″, or —SR′, wherein R′ and R″ each independently represent an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group.

20. The method of claim 18, wherein the solvent is dimethylformamide, dimethyl sulfoxide, or mixtures thereof.

21. The method of claim 20, wherein the solvent is dimethylformamide.

22. The method of claim 18, wherein the first reaction mixture is heated at about 150° C. for about one hour in an argon atmosphere.

23. The method of claim 18, wherein the actual yield of the porphine is greater than about 90%.

24. The method of claim 18, wherein the actual yield of the porphine is about 96%.

25. The method of claim 18, wherein air is bubbled through the second reaction mixture during reflux.

26. The method of claim 18, wherein oxygen is bubbled through the second reaction mixture during reflux.

27. The method of claim 18, further comprising mixing the porphine with a metal salt to form a porphine compound containing a metal.

28. The method of claim 27, wherein the porphine comprises:

where M is iron, cobalt or copper; R represents a halogenated alkyl group,

wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a substituted alkyl group; an aryl group; a substituted aryl group; an alkoxy group; a nitrogen-containing group; a sulfur-containing group; —OR′, —NR′R″, or —SR′, wherein R′ and R″ each independently represent an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group.

29. The method of claim 27, wherein the porphine comprises:

wherein R1 represents an alkyl group having from 1 to 6 carbon atoms, an aryl group, or a substituted aryl group.

30. A method of light stabilizing a colorant, comprising associating the colorant with the porphine produced by the method of claim 27.

31. A method of making an ink comprising the porphine produced by the method of claim 27.

32. A porphine produced by the method of claim 27.

33. An ink composition comprising at least one porphine produced by the method of claim 27.

34. A porphine compound having the following general formula:

where M is iron, cobalt or copper; and R represents one or more substituents having at least one atom therein, wherein the at least one atom has a spin-orbit coupling constant greater than about 200 cm−1.

35. The porphine compound of claim 34, wherein the one or more substituents have at least one atom therein with a spin-orbit coupling constant greater than about 500 cm−1.

36. The porphine compound of claim 35, wherein the one or more substituents have at least one atom therein with a spin-orbit coupling constant greater than about 2400 cm−1.

37. The porphine compound of claim 36, wherein the one or more substituents have at least one atom therein with a spin-orbit coupling constant greater than about 5000 cm−1.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 60/175,643, filed Jan. 12, 2000, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to porphines, methods for making porphines, and the use of porphines in ink compositions.

wherein R is any proton-donating moiety and M is iron, cobalt or copper. Desirably, R is SO3H,

COOH, or R1COOH wherein R1 is an alkyl group of from 1 to 6 carbons. R may also be in its corresponding salt form, such as SO3Na for SO3H or

One such porphine is Cu-meso-tetra-(2-sulfanatophenyl)-porphine (designated o-CuTPPS4) having the following structure:

An attempt to make o-CuTPPS4 is disclosed in Treibs et al., Leibigs Ann. Chem., 718, 183, 1998 (hereinafter, “Treibs”). Treibs tried to prepare o-TPPS4 from 2-formylbenzenesulfonic acid, pyrrole, and propionoic acid. However, Treibs could not isolate the resulting product. Treibs reported a yield by GLC analysis of less than about 10%.

Although porphines provide excellent light stability to colorants, some porphines are relatively unstable and/or tend to “yellow” colorant compositions containing magenta dyes. A more desirable porphine molecule would be one that has at least one of the following characteristics: (1) the porphine molecule has less tendency to “yellow” a colorant composition, (2) the porphine molecule has the ability to make the colorant composition more “blue”; and (3) the porphine molecule, when used as a colorant, has superior lightfastness properties.

Further, while some of the above-described porphines provide excellent stability to one or more colorants associated with the porphines, they do not provide an orange/red color to a composition containing the porphines.

Accordingly, there exists a need in the art for a convenient, low cost, high yield method of making porphines, and compositions containing the porphines. Further, there exists a need for improved porphines, which are capable of providing superior colorant stability while being more stable themselves and without the tendency to “yellow” colorant compositions containing magenta dyes. Finally, there exists a need in the art for a new family of compounds that may be used alone as a colorant or may be used as a colorant stabilizer for one or more colorants associated with the new compounds.

SUMMARY OF THE INVENTION

The present invention addresses the needs described above by providing a new family of porphine compounds having the following general formula:

where M is iron, cobalt or copper; R represents a halogenated alkyl group,

wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a substituted alkyl group; an aryl group; a substituted aryl group; an alkoxy group; a nitrogen-containing group; a sulfur-containing group; —OR′, —NR′R″, or —SR′, wherein R′ and R″ each independently represent an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group.

The porphine compounds may be used as a magenta colorant and/or as a colorant stabilizer for other colorants. The new porphine compounds, when used as a colorant stabilizer, do not “yellow” magenta dyes. Consequently, unstable dyes, such as Acid Red 52, do not need to be used to make a magenta composition. The result is a more “blue” magenta color and a higher porphine to dye ratio, which creates superior light stability.

The present invention also addresses the needs described above by providing processes of making the above-described porphines at a lower cost and higher yields. The resulting porphines may be used as a colorant stabilizer for a variety of colorants, especially magenta colorants.

The present invention also relates to colorant compositions having improved stability and lightfastness, wherein the colorant is one or more of the new porphine compounds. The present invention also relates to the use of the porphine compounds in ink compositions and ink sets.

These and other features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments and the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a new family of porphine compounds having the following general formula:

where M is iron, cobalt or copper; R represents a halogenated alkyl group,

wherein R1 to R77 each independently represent —H; a halogen; an alkyl group; a substituted alkyl group; an aryl group; a substituted aryl group; an alkoxy group; a nitrogen-containing group; a sulfur-containing group; —OR′, —NR′R″, or —SR′, wherein R′ and R″ each independently represent an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. Desirably, R1 to R77 each independently represent —H; a halogen; an alkyl group; a nitrogen-containing group; or a sulfur-containing group. More desirably, R1 to R77 each independently represent —H; chlorine; bromine; fluorine; iodine; a tert-butyl group; —NO2; —SO3H; —SO3Na; —SO3Cl; or —SO3Cl−pyH+. Even more desirably, R1 to R77 each independently represent —H; chlorine; bromine; fluorine; or iodine. The new compounds may be used alone as an orange/red colorant or may be used as a colorant stabilizer.

The present invention also relates to colorant compositions having improved stability and lightfastness, wherein the colorant constitutes one or more of the above-described porphine compounds. Desirably, one or more of the new porphine compounds are admixed with a solvent system, as well as other composition components. The porphines may be used alone or in combination with at least one metal or metal salt. Suitable metals and metal salts are disclosed in U.S. Pat. No. 5,891,229, assigned to Kimberly Clark Worldwide, Inc., the entirety of which is incorporated herein by reference. As an example, the metal or metal salt in a composition can comprise a lanthanide or lanthanide salt. Moreover, a typical lanthanide or lanthanide salt comprises europium or europium salts. Optionally, the new porphine compounds may be associated with a molecular includant, chelating agent, or other material to improve solubility and/or interaction of the porphine compound and other colorants, if present. Suitable molecular includants, chelating agents, and other composition materials are also disclosed in U.S. Pat. No. 5,891,229. Typical molecular includants with which the porphines may be associated include one or more cyclodextrins, for example α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, δ-cyclodextrin, hydroxypropyl β-cyclodextrin, or hydroxyethyl β-cyclodextrin.

The present invention is further directed to a convenient, fast, low cost, environmental-friendly process of making new porphine compounds. One process of making new porphine compounds proceeds by the following reaction, wherein N,N-dimethylformamide (DMF) is used as the solvent:

Group Y Aldehydes:

wherein R1 to R77 are as described above.

The above process produces TPPR4 (i.e., a porphine substituted with “R” groups) at yields of greater than 80%, and as high as about 96 to 97%. The TPPR4 is further reacted with a metal or metal salt, M, as defined above, to produce one of the porphine compounds of the present invention. The latter reaction proceeds at yields of greater than 90%, and as high as about 96 to 97%.

The reaction conditions for the above process may vary. Typically, the reaction may be carried out in a two-step process as follows. The reactants are purified by the following process or a similar purification process. The pyrrole is distilled under argon and a fraction is collected at 130° C. The aldehyde reactant(s) is purified by a Dean and Stark method using benzene as the solvent. The solution is filtered at 60° C. and the solid pumped in a vacuum oven overnight at room-temperature. The p-toluene sulfonic acid may also be purified by a Dean and Stark method using benzene as the solvent. It should be noted that a variety of one or more aldehyde reactants may be used in the above-described reaction.

In the first step, the aldehyde, N,N-dimethylformamide (DMF) and pyrrole are placed in a reaction vessel and stirred at room-temperature. The mixture is flushed with argon for about five minutes while stirring prior to heating. The mixture is then heated to 100° C. for about ten to twelve minutes. The toluene sulfonic acid dissolved in 15 ml of DMF is injected into the reaction mixture. The reaction mixture is heated to 150° C. and held at this temperature for about 50 minutes to form a porphine intermediate. DMF is removed under vacuum from the reaction mixture to yield a precipitate.

In the second step, the porphine intermediate is mixed with propionic acid. Air or oxygen is bubbled through the mixture at reflux for a period of time to yield a finished product. Conversion of the intermediate to the finished product may be monitored using an UV/VIS spectrometer. Reflux time may vary, but usually the reflux time is up to about 10 hours to convert the porphine intermediate to TPPR4. The TPPR4 is further reacted with a metal or metal salt, M, as defined above, to produce one of the porphine compounds of the present invention.

The choice of solvent in the first step of the above process may be any solvent, which enables the efficient production of TPPR4 and the new porphine compounds. Suitable solvents include, but are not limited to, DMF, dimethyl sulfoxide (DMSO), and dimethyl acetamide.

In one embodiment of the present invention, porphine compounds having superior lightfastness properties are produced having the following general formula:

where M is iron, cobalt or copper; and R represents one or more substituents having at least one atom therein, wherein the at least one atom has a spin-orbit coupling constant greater than about 200 cm−1. Suitable atoms having a spin-orbit coupling constant greater than about 200 cm−1 include, but are not limited to, halogens. Desirably, the porphine compound contains at least one substituent having at least one atom therein, wherein the at least one atom has a spin-orbit coupling constant greater than about 500 cm−1. More desirably, the porphine compound contains at least one substituent having at least one atom therein, wherein the at least one atom has a spin-orbit coupling constant greater than about 2400 cm−1. Even more desirably, the porphine compound contains at least one substituent having at least one atom therein, wherein the at least one atom has a spin-orbit coupling constant greater than about 5000 cm−1. In some porphine compounds, there may be a combination of two or more atoms wherein one atom has a spin-orbit coupling constant greater than about 500 cm−1 and another atom has a spin-orbit coupling constant greater than about 5000 cm−1. Any combination of such substituents is considered to be within the scope of the present invention.

It is believed that the above-described porphine compounds of the present invention possess superior lightfastness properties due to their reduced time in the excited state, as well as, their lower probability of being in the excited state. The presence of one or more R groups in the porphine having one or more substituents with high “Z” values (i.e., atomic number) produces the so-called “heavy atom effect” that arises from the coupling of the spin angular momentum and orbital angular momentum. This so-called “spin-orbit coupling”, which generally increases with increasing Z values, enhances the rates of normally spin-forbidden electronic transitions, which enables the distribution of vibrational energy at an excited state, resulting from exposure to light, intramolecularly. The “intramolecular quenching” of the molecule results in rapid quenching of the excited state back to the ground state. The net effect being a much smaller concentration of excited state species at any one time. A general discussion of “heavy atom effect” and “spin orbital coupling”, as well as values for spin orbit coupling constants, may be found in the Handbook of Photochemistry (Murov et al.), 2nd ed., pages 338-341, 1993, the entirety of which is incorporated herein by reference.

The present invention is further described by the examples which follow. Such examples, however, are not to be construed as limiting in any way either the spirit or scope of the present invention. In the examples, all parts are parts by weight unless stated otherwise.

EXAMPLE 1Preparation of TPPS4 Intermediate

Tetra-(3-sulfanato-4-methoxyphenyl)-porphine (designated TPPS4) was prepared by mixing the following reactants in DMF solvent: pyrrole; 2-methoxy-5-formylbenzene sulfonic acid, sodium salt; and p-toluenesulfonic acid. Prior to mixing the reactants, pyrrole was distilled under an argon atmosphere with the fraction boiling at 130° C. collected. The 2-methoxy-5-formylbenzene sulfonic acid, sodium salt (Aldrich) was purified by a Dean and Stark method using benzene as the solvent. The solution was filtered at 60° C. and the resulting solid was pumped in a vacuum oven overnight at room-temperature. The DMF (99.9% anhydrous grade available from Aldrich) was used without further purification. The p-toluenesulfonic acid was purified by a Dean and Stark method using benzene as the solvent.

A mixture of 5.0 g of the pyrrole, 15.6 g of the 2-methoxy-5-formylbenzene sulfonic acid, sodium salt, and 200 ml of the DMF was placed into a 500 ml three-necked, round-bottom flask fitted with a magnetic stir bar, condenser, thermometer, and argon gas bubbler inlet. The reaction mixture was flushed with argon for five minutes with stirring prior to heating. The mixture was then heated to 100° C. for about 10-12 minutes at which time 0.76 g of p-toluenesulfonic acid was syringed into the reaction mixture. The p-toluenesulfonic acid was dissolved in 15 ml of DMF. The clear, colorless reaction mixture turned red to blood red to brown red to red black in one to two minutes. The reaction mixture was heated to 150° C. and held at this temperature for about 50 minutes.

After about 50 minutes at 150° C., the reaction was cooled in an ice bath for about 20 minutes. The DMF was removed under vacuum to yield a precipitate. The wet solid was then placed in a vacuum oven overnight at ambient temperature to dry the solid.

EXAMPLE 2Preparation of TPPS4 in an Argon Atmosphere

Ten grams of the dried powder of Example 1 was mixed with 200 ml of propionic acid in a 500 ml three-necked round-bottom flask. The mixture was heated at reflux in an argon atmosphere. The reaction mixture was monitored by a UV/VIS spectrometer to follow conversion of the TPPS4 intermediate to TPPS4.

The mixture was refluxed for about 67 hours to yield a small amount of TPPS4 having an absorption peak at 412 nm.

EXAMPLE 3Preparation of TPPS4 in an Open Air Condenser

Ten grams of the dried powder of Example 1 was mixed with 200 ml of propionic acid in a 500 ml three-necked round-bottom flask. The mixture was heated at reflux with an open air condenser. The reaction mixture was monitored by a UV/VIS spectrometer to follow conversion of the TPPS4 intermediate to TPPS4.

The mixture was refluxed for about 67 hours. After 10 hours of reflux, conversion to TPPS4 was substantially completed. Full conversion to TPPS4 having an absorption peak at 412 nm was completed at 67 hours.

EXAMPLE 4Preparation of TPPS4 with Air Bubbled Into the Reaction Mixture

Ten grams of the dried powder of Example 1 was mixed with 200 ml of propionic acid in a 500 ml three-necked round-bottom flask. The mixture was heated at reflux while air was bubbled into the reaction mixture. The reaction mixture was monitored by a UV/VIS spectrometer to follow conversion of the TPPS4 intermediate to TPPS4.

The mixture was refluxed for 10 hours. Full conversion to TPPS4 having an absorption peak at 412 nm was completed in 10 hours.

EXAMPLE 5Preparation of CuTPPS4 Colorant Stabilizer

Cu-meso-tetra-(3-sulfanato-4-methoxyphenyl)-porphine (designated CuTPPS4) was prepared by the following reaction. A mixture of 0.31 g of copper powder, 5.0 g of TPPS4 from Example 4, and 50 ml of water were added to a 200 ml round-bottom flask fitted with a condenser and magnetic stirrer bar. The mixture was heated in reflux for three hours. The hot mixture was evaporated down to about 10 ml and chilled. Acetone was added to the mixture. The precipitate was filtered and washed with hexane and toluene. The precipitate was dried under vacuum to yield 3.9 g of a solid. The yield was about 72%.

TLC showed a clean product of CuTPPS4.

EXAMPLE 6Preparation of a Magenta Composition Containing CuTPPS4 As the Colorant

A magenta ink was prepared having the following composition wherein the components are given in weight %:

Component

Weight %

DI Water

85.63

Borax

1.90

HCl (1N)

1.57

EDTAo2Na

0.10

CuTPPS4 (Example 5)

0.50

Ethylene Glycol

5.00

Glycerine

5.00

GIV-GARD DXN ®

0.20

COBRATEC ® 99

0.10

The ink was prepared using the following components: deionized water; borax; hydrochloric acid as a buffer/pH adjuster; EDTA or sodium salts thereof as a chelating agent; ethylene glycol and glycerine as wetting agents; GIV-GARD DXN® (Sigma-Aldrich, Milwaukee, Wis.) as a biocide; COBRATEC® 99 (PMC Industries, Cincinnati, Ohio) as a corrosion inhibitor; and CuTPPS4 from Example 5 as the dye.

The magenta composition was printed onto a photoglossy medium to produce a light-stable magenta having color gamut with an enhanced blue component.

EXAMPLE 7Preparation of a Magenta Composition Containing CuTPPS4 As a Colorant Stabilizer

A magenta ink was prepared having the following composition wherein the components are given in weight %:

Component

Weight %

DI Water

81.54

Borax

1.90

HCl (1N)

1.57

EDTAo2Na

0.10

CuTPPS4 (Example 5)

0.50

Ethylene Glycol

5.00

Glycerine

5.00

GIV-GARD DXN ®

0.20

COBRATEC ® 99

0.10

Reactive Red 187

2.89

Acid Red 52

1.20

The ink was prepared using the following components: deionized water; borax; hydrochloric acid as a buffer/pH adjuster; EDTA or sodium salts thereof as a chelating agent; ethylene glycol and glycerine as wetting agents; GIV-GARD DXN® (Sigma-Aldrich, Milwaukee, Wis.) as a biocide; COBRATEC® 99 (PMC Industries, Cincinnati, Ohio) as a corrosion inhibitor; Reactive Red 187 and Acid Red 52 as dyes; and CuTPPS4 from Example 5 as a colorant stabilizer.

The magenta composition was printed onto a photoglossy medium to produce a light-stable magenta having color gamut with an enhanced blue component.

EXAMPLE 8Preparation of o-TPPS4 Precursor

Tetra-(2-sulfanatophenyl)-porphine (designated o-TPPS4) was prepared from the following reactants in a DMF solvent: pyrrole; 2-formylbenzene sulfonic acid, sodium salt; and p-toluenesulfonic acid. Prior to mixing the reactants, pyrrole was distilled under an argon atmosphere with the fraction boiling at 130° C. collected. The 2-formylbenzene sulfonic acid, sodium salt (Aldrich) was purified by a Dean and Stark method using benzene as the solvent. The solution was filtered at 60° C. and the resulting solid was pumped in a vacuum oven overnight at room-temperature. The DMF (99.9% anhydrous grade available from Aldrich) was used without further purification. The p-toluenesulfonic acid was purified by a Dean and Stark method using benzene as the solvent.

A mixture of 5.0 g of the pyrrole, 15.6 g of the 2-formylbenzenesulfonic acid, sodium salt, and 200 ml of the DMF was placed into a 500 ml three-necked, round-bottom flask fitted with a magnetic stir bar, condenser, thermometer, and argon gas bubbler inlet. The reaction mixture was flushed with argon for five minutes with stirring prior to heating. The mixture was then heated to 100° C. for about 10-12 minutes at which time 0.76 g of p-toluenesulfonic acid was syringed into the reaction mixture. The p-toluenesulfonic acid was dissolved in 15 ml of DMF. The clear, colorless reaction mixture turned red to blood red to brown red to red black in one to two minutes. The reaction mixture was heated to 150° C. and held at this temperature for about 50 minutes.

After about 50 minutes at 150° C., the reaction was cooled in an ice bath for about 20 minutes. The DMF was removed to yield a precipitate. The wet solid was then placed in a vacuum oven overnight at ambient temperature to dry the solid.

EXAMPLE 9Preparation of o-TPPS4 in an Argon Atmosphere

Ten grams of the dried powder of Example 8 was mixed with 200 ml of propionic acid in a 500 ml three-necked round-bottom flask. The mixture was heated at reflux in an argon atmosphere. The reaction mixture was monitored by a UV/VIS spectrometer to follow conversion of the o-TPPS4 precursor to o-TPPS4.

The mixture was refluxed for about 67 hours to yield a small amount of o-TPPS4 having an absorption peak at 412 nm.

EXAMPLE 10Preparation of o-TPPS4 in an Open Air Condenser

Ten grams of the dried powder of Example 8 was mixed with 200 ml of propionic acid in a 500 ml three-necked round-bottom flask. The mixture was heated at reflux with an open air condenser. The reaction mixture was monitored by a UV/VIS spectrometer to follow conversion of the o-TPPS4 precursor to o-TPPS4.

The mixture was refluxed for about 67 hours. After 10 hours of reflux, conversion to o-TPPS4 was substantially completed. Full conversion to o-TPPS4 having an absorption peak at 412 nm was completed at 67 hours.

EXAMPLE 11Preparation of o-TPPS4 with Air Bubbled Into the Reaction Mixture

Ten grams of the dried powder of Example 8 was mixed with 200 ml of propionic acid in a 500 ml three-necked round-bottom flask. The mixture was heated at reflux while air was bubbled into the reaction mixture. The reaction mixture was monitored by a UV/VIS spectrometer to follow conversion of the o-TPPS4 precursor to o-TPPS4.

The mixture was refluxed for 10 hours. Full conversion to o-TPPS4 having an absorption peak at 412 nm was completed in 10 hours.

EXAMPLE 12Preparation of o-CuTPPS4 Colorant Stabilizer

Cu-meso-tetra-(2-sulfanatophenyl)-porphine (designated o-CuTPPS4) was prepared by the following reaction. A mixture of 0.31 g of copper powder, 5.0 g of o-TPPS4 from Example 11, and 50 ml of water were added to a 200 ml round-bottom flask fitted with a condenser and magnetic stirrer bar. The mixture was heated in reflux for three hours. The hot mixture was evaporated down to about 10 ml and chilled. Acetone was added to the mixture. The precipitate was filtered and washed with hexane and toluene. The precipitate was dried under vacuum to yield 3.9 g of a solid. The yield was about 72%.

A magenta ink was prepared having the following composition wherein the components are given in weight %:

Component

Weight %

DI Water

81.54

Borax

1.90

HCl (1N)

1.57

EDTAo2Na

0.10

o-CuTPPS4

0.50

(Example 12)

Ethylene Glycol

5.00

Glycerine

5.00

GIV-GARD DXN ®

0.20

COBRATEC ® 99

0.10

Reactive Red 187

2.89

Acid Red 52

1.20

The ink was prepared using the following components: deionized water; borax; hydrochloric acid as a buffer/pH adjuster; EDTA or sodium salts thereof as a chelating agent; ethylene glycol and glycerine as wetting agents; GIV-GARD DXN® (Sigma-Aldrich, Milwaukee, Wis.) as a biocide; COBRATEC® 99 (PMC Industries, Cincinnati, Ohio) as a corrosion inhibitor; Reactive Red 187 and Acid Red 52 as dyes; and o-CuTPPS4 from Example 12 as a colorant stabilizer.

The magenta composition was printed onto a photoglossy medium to produce a light-stable magenta having color gamut with an enhanced blue component.

EXAMPLE 14Preparation of Tetranaphthyl Porphine (TNP)

Tetra-(1-naphthyl) porphine (designated TNP) was prepared from the following reactants in a DMSO solvent: pyrrole and 1-naphthaldehyde. Prior to mixing the reactants, pyrrole was distilled under an argon atmosphere with the fraction boiling at 130° C. collected. The 1-naphthaldehyde was distilled under vacuum to purify. A mixture of 6.0 g of pyrrole, 13.7 g of 1-naphthaldehyde, and 120 ml or DMSO were heated at reflux for 2 hours. The reaction solution was cooled and the DMSO solvent partially removed under vacuum. The solid that was present was filtered off and washed with 60 ml of methanol, 60 ml of hot water, and 12 ml of cold methanol. The resulting solid was then dried in a vacuum oven at ambient temperature overnight.

Conversion to TNP was monitored by UV/VIS spectrometry (λmax 420 nm). The yield of TNP was about 79%.

EXAMPLE 15Preparation of CuTNP Colorant

The compound Cu-meso-tetra(1-naphthyl)-porphine (designated CuTNP) was prepared by the following reaction. A mixture of 0.24 g of Cu(O2CCH3)2oH2O, 1 g of TNP from Example 14, and 73 ml of DMF was heated to 120° C. for 60 minutes at which time the reaction had changed to reddish in color. The reaction mixture was cooled and poured into 200 ml of ice water, and the resulting mixture was extracted with diethyl ether. After washing the ether with water and drying over MgSO4, the solvent was removed under vacuum to yield the desired CuTNP. The product was characterized by mass spectrometry (875 M+) and UV/VIS spectrometry (λmax 420 nm, 540 nm). The yield of CuTNP was 77%.

Having thus described the invention, numerous changes and modifications thereof will be readily apparent to those having ordinary skill in the art, without departing from the spirit or scope of the invention.